Preparation or regeneration of rubber or caoutchouc.



cries;

FRANCIS WILLIAM PASSMORE, OF LONDON, ENGLAND.

PREPARATION OR REGENERATION OF RUBBER: 0R CAOUTCEOUC.

To all whom it may concern:

Be it known that I, FRANoIs WILLIAM PASSMORE, of'63 Queen Victoria street, in the city of London, England, consultin chemist, have invented certain new an useful Improvements in the Preparation or Regeneration of Rubber or Caoutchouc, of which the following is a specification.

This invention relates to the preparation or regeneration of rubber or caoutchoucfrom rubber Waste, crude rubber or other material containing the same.

Cineol or eucalyptol, either synthetically produced or obtained from essential oils, or it may be essential oils containing the said substance, possess the property of dissolving caoutchouc and I have found that caoutchouc may be recovered from such solution in a high state of purity and capable of being vulcanized. 7

By the em loyment of cineol or eucalyptol as a solvent t dr caoutchouc, I am able to prepare concentrated solution of caoutchouc at moderately low temperatures, the characteristic physical qualities of the caoutchouc obtained being unafiected, While impurities such as mineral matters, tissues and the like insoluble in cineol or eucalyptol can be removed by mixing the concentrated eucalyptol solution of caoutchouc with a volatile diluent benzene or like liquids miscible with eucal tol and whieh 'do not precipitate the caoutc one from such solution. The caoutchouc may be recovered from suchsolution by distilling off the eucalyptol with steam or by precipitating the caoutchouc from the eucalyptol solution by means of alcohol or acetone or a similar precipitating agent mis cible with eucalyptol or cineol.

The manner in which the invention can be carried into effect will be understood from the following example.

Example I: The crude rubber, rubber waste, or caoutchouc containing material in the form of scraps is reduced to a ulp by suitable mechanical means, and t ie n. digested, preferably in a closed digester provided with a stirring arrangement, with 4 to 8 parts by weight of eucalyptol to one part of j The contents of the digester are scrap. heated by means of a bath to a temperature oughly stirred until solution is complete. The solution of caoutchouc, which is of a very thick viscous character is thinned with three, four or more volumes of benzene or Specification of Letters Patent. Application filed March 30, 1907. Serial No. 866,509.

Patented June 8, 190).

then run into a still and the benzene or other volatile diluent distilled off. Two or three volumes of water are then added to the residue in the still and steam is blubbered through the mass until the Whole of the eu calyptol is driven over. The recovered caoutchouc is then drained from the water and dried on hot rollers in the usual way.

If desired the benzene or other diluent may be added to the material in the digester, but in general I prefer toadd it after the mass has been removed from the digester.v

Example II: The rubber waste or raw caoutchouc containing material is reduced to a pulp and dissolved in eucalyptol and freed from mineral and other extraneous matter in the same manner as described in Example I. The benzene or other diluent is then distilled off and to the gummy eucalyptol solution an excess of alcohol or acetone is added with constant stirring until the whole of the caoutohouc is preci itated as a gummy homogeneous mass. T e liquor is poured oil and the mass washed with alcohol until free from eucalyptol and finally washed with warm water and dried. The alcohol or acetone may be recovered from the cured off liquor by distillation and returned to the manufacture.

It will be understood that the above examples are given as instances only, and that I do not confine myself to the proportions and working details given therein, which may be varied without departing from the spirit of the invention.

What I claim and desireto secure by Letters Patent is 1'. A process of preparing caoutehouc from rubber waste or other material containing the same, comprising dissolution of said 1115)," terial in-eucalyptol, addition of a volatile diluent, separation of undissolved matter from the dilute solution, and separation oi the caoutchouc from the eucalyptol.

2. A process of. preparing caoutchouc from rubber waste or other material. containing the same, comprising dissolution. of said maof about l20-140 (1., the mass being thor- I 3., A process of preparing caoutchouc from I In witness whereof, I have hereunto signed rubber waste or other material containing my name in the presence of two subscribing 1 the same, comprising dissolution of saidmw witnesses. teria'l 01' eucalyptol, addition of benzene, to

' 5 the solution, separation of nndissolved mat- FRANCIS WILLIAM PMSSMURE' ter from the mlxtnre, dlstilhng of? of the ben- Witnesses: zene and separation of the caoutchouc from WILLIAM HEATON 'inolms,

the eucalyptol. H. D. JAMESON. 

